Meiosis

Review: Homologous chromosomes Gametes Gene Diploid (2n) Haploid (n) Somatic cells Autosomes Sex chromosomes Mitosis

Why is sexual reproduction more beneficial to a species than asexual reproduction – over time?

Asexual Reproduction

Sexual Reproduction leads to diversity!

How does meiosis result in diversity? Homologous chromosomes trade parts during Prophase I – crossing over.crossing over.

Homologous chromosomes get shuffled – Independent Assortment

You never know which of the homologous chromosomes will end up in which egg.

Where are gametes made in the human body? Ovary

Meiosis – Reduction Division Watch this process and think about how meiosis (the formation of gametes) is different from mitosis. meiosis

How is a zygote formed?

Meiosis: Males vs. Females Males: Meiosis and sperm production begins at puberty Continuous process that males will always undergo – takes 9 weeks Females: Meiosis and egg production begins before birth. Process stops abruptly, and does not begin again until puberty At puberty, one egg each month resumes meiosis and finishes its development Process stops when a women reaches menopause (around 50 years of age) Meiosis of a singe egg could take 50 years to complete!

Comparison Comparison of mitosis and meiosis Skin Cells Egg Cells Diploid Haploid Somatic Cells or Body CellsGametes or sex cells

Meiosis Review

Diploid Vs. Haploid?

Gametes Vs. Somatic Cells

Can you explain this diagram?

Meiosis Foldable Draw and Label: Diploid cells Homologous chromosomes Crossing over Haploid cells Explain: Are the newly formed haploid cells genetically identical to the parent cell? Explain why or why not.

Meiosis Review The Meiosis Square DanceMeiosis Square Dance Meiosis I Animation Meiosis II Animation